Audible warning signal



June 18, 1940. J. scQFlELD 2,204,705

AUDIBLE WARNING SIGNAL Filed June 18, 1957 i In ENTu' t :0 B 1 TT DRNEY Patented June 18, 1940 UNITED. STATES 2,20 ,705 PATENT] 3 OFFICE 1 AUDIBLE WARNING SIGNAL Theodore J. Scofield, Jackson, Mich.) assignor to The Sparks-Withington Company, Jackson, Mich., a corporation of Ohio Application June 18, 1937, Serial No. 148,981 I 7 Claims. (01. 177-4 This invention relates to an audible warning signal forvehicles, for instance automobiles, and pertains more particularly to a warning signal in which a vibratory diaphragm is actuated by an electric motor of the magnetic type.

Signaling horns of this type are frequently, in present day practice, usedlin pairs, tuned to different frequencies. These horns are operated simultaneously, and the current for the motors being relatively heavy, islcontrolled by a relay which in turn is controlled by a. manually operated switch of the push button-type. In my copendingapplication Serial Number123,887, filed February 3, 1937, I have shown a pair of electrically operated horns of the magnetic type wherein a relay of such size and design as to satisfactorily control the heavy current necessary to operate both horns is mounted on a diaphragm case member of one of the horns of the group, andwithin the cover or cap therefor- ;Prior to the invention of my said application, the relay for such dual horns has always been mounted exteriorly of the horns, usually on a common bracket support for the horns.

The main object of the present invention is to provide a mounting structure for warning signals of the above mentioned type which isan improvement upon the structure shown in said co-pending application Serial No. 123,887.

have, by a change in the structure and arrangement of the parts of the contact stack for the motor, adapted the same to support also the :relay for closing the circuit to the motor in such a manner that there is obtained an appreciable saving in materials and labor in the construction and assembly thereof.

The above and otherobjects and advantages pertaining to the structure ofthe contact stack and the arrangement of the parts thereof, and the manner of connectingthe relay therewith, will more fully appear from the following description, taken in conjunction with the accompanying drawing, in which:

Figure l is a perspective view showing a complete dual horn assembly embodying the various features of this invention with a portion ofone of the projectors broken away. i i

Figure 2 is a top plan view of a portion of Figure 1 with the horn caps removed.

Figure 3 is an enlarged detail transverse sectional view taken on line 3'- 3,Figure 2.

Figure 4 is a detail vertical sectional "view taken on line 4--4, Figure 2, illustrating a portion of the cap mounted upon the diaphragm case sections. l r

Figure ,5 is a perspective view of the upper positioned or rigid contact arm, andv the relay porting the horns.

In carrying out theabove mentioned object, I

are mounted uponavcommon bracket 3 adapted to be attached by bolts or their equivalent, to a convenient portion of the motor vehicle for sup- These hornsare constructed similarly except for the contact stacks; the contact stack for one of the horns, as I, having the relay associated therewith, being of special construction, whereas the contact stack of the other born, as 2', may be of any suitable well known construction. Each of these horns comprises a metal rear diaphragm case 5 having a central portion displaced laterally to form an integral substantially cylindrical cup-shaped member 6, said member being provided with a central opening 1 for the reception of an electro-magnet,

presently described. A diaphragm 8 is clamped between the rear diaphragmcase 5 and afront diaphragm case 9 bybolts l passing through aligned holes provided in. the marginal portions of the diaphragm and diaphragm case section. The front diaphragm case. section 9 is composed of metal and has the central portionthereof inclined outward, and arranged in opposed relation to the central portion 6 of the rear diaphragm case section for forming a diaphragm chamber H therebetween.

The central portion of the front case section 9 is provided with a centrally disposed forward extending annular flange 12, to which is secured in any suitable manner, a horn proper, or projector I3. The electro-magnet previously referred to may comprise a case member l4 adapted. to extend from. theinner side of the rear case section outward through the opening 1, and is secured to the inner adjacent side of said case section in any suitable manner, as by legs I5, spot welded to said section. As indidated in Figure 4, the case I4 may be provided with a pair of transversely disposed slots It for the reception of a pre-formed field coil H, which is constructed in any well known manner, and electrically insulated from the said case M.

The diaphragm 8 is provided with a central opening in alignment with the opening 1 in the rear diaphragm case 5 for the reception of a bushing 20, which is provided with internal threads for the receptionof the lower threaded end of a spacing sleeve 2 I. This sleeve 2| extends rearward from the diaphragm 8 and bushing 20 through a central opening 22 provided in the case M, and has the upper end thereof arranged in engagement with the armature 23 positioned adjacent the rear side of the case M. The lower or forward end of the sleeve 2! projects a relatively short distance beyond the other face of the bushing 20, and has mounted thereon in any suitable manner a collar 24, which is slidably connected with the sleeve to form a fingerpiece by which the sleeve may be rotated to effect proper adjustment of the armature 23 with respect to the case l4. v

Mounted within the sleeve 2| is a bolt orstud 25, which has the head thereof arranged adjacent the collar 24 and spaced therefrom by washer 26. The other end of the bolt 25 extends rearward from the sleeve 2| through a central opening provided inthearmature 23 to some distance-at the rearof said armature. Mounted upon the bolt 25 is a bearing collar 21, which is seated in a suitable socket or recess provided in the outer or rear face of the armature 23, and which bears against a washer 28 mounted upon the stud or bolt 25 between the collar 21 and a nut 29, screw-threaded on the outer or rear end portion of the stud 25.

Clamped between the washer 28 and nut 29 is one end of a yielding support 30, which, in this instance is a fiat spring member connected at the other end in any suitable manner, as by stud 3|, to the rear diaphragm case section 5 at one side 'of the opening 1.

The structure thus far described is of conventional form and, as hereinbefore stated, may be alike in both horns I and 2. It will be understood that this conventional construction forms no part of my invention, and that other comparable constructions might be substituted therefor.

An automatic circuit breaker is provided for each horn, as is usual in motors of this type, to effectintermittent energizing and de-energizing Iof the magnet in synchronism with the movement of the diaphragm away from and toward the coil case M. One of these circuit breakers is of specialconstruction in that it is adapted to support a relay. This relay is so connected with the circuit breaker that upon actuation of a manually controlled switch or horn button, it will complete the circuit through the horn electro-magnets so as to avoid passing the heavy current required to operate the electro-magnets through the manually controlled switch or horn button.

- Not only is the contact stack of the circuit breaker of special construction for supporting the relay, but the relay itself must be of such a size and structure as to enable it to be mounted within the case or cover of a standard horn of the type under consideration, while at the same time making the relay positive in action and capable of operating successfully despite the vibration of thehorn when said horn is being operated.

That is, the electro-magnet of the relay should be strong so as to hold the armature closed against vibration. Also, the relay armature should be light, particularly at its free or contact end, and the armature spring should be relatively weak, both of which factors tend to reduce the possibility of. accidental opening of the relay. In order to minimize the effect of the horn vibration,

.the relay and the specially constructed contact stack supportably assooiat'edtherewith should be preferably combined with the horn, the pitch or frequency of which is further from the natural period of vibration of the relay. Ihis will ordinarily be the horn of higher pitch.

The-specially constructed contact stack containing this invention and which is shown as mounted in the horn I, comprises, as illustrated more particularly in Figures Band 4, a U-shaped supporting frame 32, which may be, a sheet metal stamping, secured in inverted position to the central portion 6 of the rear case section 5 by electric welding or other'suitable means adjacent one side of the opening I.

To the upper transverse portion of the frame 32 is secured a pair of contact arms 33 and 34.

These arms 33 and 34 are arranged in electrical insulated spaced relation to each other and to the frame 32 by insulating plates or spacers" 35 and 36 and tubes 31. These tubes 3'! surround a pair of screws 38 which extend downward through aligned holes provided in the contact arms and insulating plates into screw-threaded engagement with the frame'32 for securing said arms and plates tosaid frame. The arms 33 and 34 are positioned, as more particularly shown in Figure 4, adjacent the upper end of the contact stack in close proximity to each other and, in the structure shown, are not only insulated from each other by the plate 36, but are also electrically insulated from the frame 32 and screws 38 by the tubes 31 and plates 35, as illustrated more particularly in 'Figure 3. The arm 33 is provided with a contact point 33 which is adapted to engage a similar contact point 31! mounted on the arm 34. extend outward from the support 32 0ver the armature 23and terminate in spaced relation to the stud 25. a

The arm 33, in this instance is a rigid member, while the arm 34 is a flexible member :in the form of a flat spring adapted to be actuated by the stud 25 through the medium of a nut 39 screw-threaded on the outer reduced end portion 25" of said stud to move the contact point 34' out of electrical connection with the contact rm the stud 25'by a lock nut 40.

Mounted in the contact stack beneath the contact arm 34 and in electrical contact therewith,

is a terminal plate 42. The lower side of .the terminal plate 42 is insulated by one of the in- The contact arms 33 and34 sulating. plates 35 which is mounted upon the.

screws 38 and tubes 31. Beneath the terminal plate 42 and the sub-adjacent insulating plate 35 is a second terminal plate 43 which is also electrically insulated from the contact arms 33' and 34, the terminal plate 42 and the bracket,

32 by insulating plates 35 and tubes 3], as shown in Figure 3. One'side of the terminal plate 43 extends downward in slightly spaced relation to the adjacent vertical leg of the bracket 32 and then outward to form a shelf 44 for supporting an. electro-magnetic relay 45.

The relay 45v includes a coil 46 of insulated wire wound on a core 41 between insulating heads or spool ends lt and 49 in the well known manner. The core 41 has its lower end 41' reduced in v diameter and extended through a suitable aperture in the shelf, and may be peened or riveted over the adjacent surface of the shelf 44 for firmly securing the core and the relay coil 46 carried thereby to said shelf. The lower insulating head 49 is provided with an extension 50 carrying a screw terminal :51 to'which is electrically connected one end-of the coil 46. The other end of the coil '46 maybe electrically connected to the core 41 and thence to the terminal plate 43.1171

,cover 58 may be secured to the case seetion 5" in,

"Ametal contact plate 52,715 mounted between the enlarged upper end of the core 4'lland the upper insulating head, and carries a contact point 52, which is adapted to cooperate with a similar contact point 53 mounted ongthe armature 53 of the relay 45. The armature 53 is a relatively light member and is supported by and electrically connectedto thecontact arm33 by a fiat metal spring 54, i l l As illustrated more clearly in Figures 5 and 6,

the shelf 44 and the relay armature 53 are preferably offset fromthe contact stack toward the centerof the horn mechanism, so as to permit enclosure of the relay within the conventional horn cap with ample clearance.

An electrical resistance 56 of any suitable con struction is connectedbysuitable Wires or electric conductors to the contact arm 33 and the terminal plate 42, and therefore across the contactpoints 33' and 34 ,Lfor maintainingthe field coil l1 partially energized during the periods the at the contact points slightly greater diameterthan the rear case section for the purpose of supporting the cover. The

any suitable well known manner, as through the medium of a screw 59, which has threaded engagement with a suitable bracket (not shown) mounted upon the case section 5. A suitable grommet 60 is arranged inthe cover 58 near the lower edge thereof inorder to provide for the passage of the exterior wiring of the horn, as hereinafter described. e i a CJne end of the field coil i1 is connected by a wire or electrical conductor 6| tothe terminal plate42 and thence to the contact arm 34, and the other end may be grounded to the horn case, for

example by connecting it under the head of one of the screws38, as illustratedin Figures 2 and 3. Another wire 62 is connected at oneen d to the terminal plate 43, passestthrough the grommet BB, and serves to connect the horn to one side of a battery B, the other side of which may be grounded. A wire 63, likewise passing through the grommet .60, serves to ,connect theterminal 5| of the relay coil 46 to one side of .a horn buttonjor other switch S, the other side, of which may also be grounded. A third wire 64 passing through the grommet B connectsthe contact arm 33 of horn l to the contactarm 33 of horn2,

thereby permitting the hornsto be blown in unifor. it i a The operation of this circuit willbe evident from an examination of Figure 7. When the push button S is closed, a circuit is completed from the battery B through wire 62, terminalplate '43,

shelf 44, core 41, relay coil 45, screw terminal wire 63 and switch S to ground G, and thence back to the battery B. Theciirrent thus passing 5 through the relay coil 46actuates the armature 53 and closes a circuit from the battery B through wire 52, terminal plate 43, shelf 44, core 41, contact plate 52, contacts 52' and 53', armature 53, spring 54, contact arm 33, contacts 33' and 34', contact. arm 34, terminal plate 42, wire 6|, field coil l1, and thence to ground and back to the battery. The consequent energization of the field coil ll draws the armature 23 toward the case l4 and breaks the circuit just described at the contacts 33' and 34', but current still continues to how therethrough, but to a lesser amount, through the resistance 56, in a manner and for a purpose well understood in this art. The re- 'sultant partial de-energization of the field coil relay 45 is mounted will pass to the contact plate 33 of the companion horn Zthrough the medium of the wire 64. It will thus be seen that the motor contained in the horn 2 willbe actuated simultaneously with the motor contained in the horn I.

As soon as the switch or horn button S isreleased, the circuit passing through the relay coil 46 will be opened, thereby causing the armature 53 to be moved away from the core 41 by the action of the spring 54 and thereby open the circuit associated with the horn motors by the movement r v of the contact point 53 out of engagement with the point 52'. I It will thus be seen that onlya relatively light current will pass through the horn button Swhile' the relatively heavy current required to operate the electro-magnets of the horns I and 2,.is shunted around the switch S and passed directly to the horn lmotors.

Furthermore, it will be noted that by mounting the relay 45 insideof the cover 58 and upon the contact stack, not only are there no terminals exposed to the outside atmosphere, which and the emission of an audible eliminates to a marked extent the possibility I of shortcircuiting of the mechanism or otherwise getting out of repair, but the, entire assembly is more economical to manufacture. That is, the construction and arrangement of the parts described above enable an appreciable saving in the cost of a Warning signal due to the elimination of a separate support for the relay and of a separate relay housing, wires, terminals, and so forth. I In addition, the adapting of the contact stack to support the relay by merely extending two previously employedmembers thereof, namely, 3

the contact arm 33 and terminal plate 43, to support the armature and electro-magnet, respectively, of the relay it, provides a unit which less expensive and includes fewer parts than has heretofore been possible to obtain inthe conventional structures. 3 a It will be apparent that the relay construction hereinabove described is equally applicable to a single horn requiring heavy current or to three or more horns in lieu of the dual horn installation illustrated by way of example.

While I have described the preferred construction and arrangement of parts of the warningrsignal, I do not wish to be limited to the exact structure shown, as various changesand modifications may be made therein without departing from the spirit of the'invention as set forthin the appended claims.

1. In a warning signal ofthe class wherein a diaphragm carried by a frame is actuated by an electric motor of the vibratory type mounted on said framemand having an electric supply circui-ttherefoi', in combination, a contactstack secured to the frame and including a. pair of coacting contact arms connected in series in, the motor current supply circuit, a relay. having switch means mounted in the contact stack and connectedtin said motor circuit in series with said contact arms and adapted to be actuated upon the coil of the relay being energized for closing said motor circuit, and a coil supporting member for said relay clamped in said contact stack,

2. In a warning signal having a diaphragm tacts being secured in the contact stack and connected in said motor circuit in series with said contact arms, and a coil supporting member for said relay clamped in said contact stack and forming a common terminal for one end of said relay coil and for one of said relay contacts. 3. In a warning signal having a diaphragm carried by a frame and actuated by the movement of an electric motor of the vibratory type mounted on said frame and having an electric supply circuit therefor, in combination, a pair of coacting contact arms clamped in a contact stack secured to the frame to be actuated by the movement of the electric motor, said. contact arms being connected in series in the motor current supply circuit, a relay comprising an energizing coil, an armature and a pair of con tacts, said contacts being secured in the contact stack and connected in series in said motor circuit, and a coil supporting member for said relay clamped in said contact stack and forming a common terminal for one end of said relay coil and for oneof said relay contacts, one of said contact arms being electrically connected to said relay armature. v

4. In a warning signal of the class having a diaphragm actuated by an electric motor of the magnetic type, a supporting frame for said diaphragm and motor, a circuit for said motor including a source of potential, in combination,

a pair of coasting contact arms having a common support mounted on the frame, said arms being connected in series in said motor circuit, one of said armsbeing operatively connected to the diaphragm to effect intermittent energizing and de elnergizing of the .motor in synchronism with the movement of said diaphragm, a relay connected in said circuit having the coil thereof supported by said common support and the armature thereof resiliently supported by one of the contact arms and electrically connected therewith, and switch means associated with the relay armature so constructed and arranged that current will be supplied to said motor circuit upon operation of the relay.

1 In ashorn of :the' class'ahaving a diaphragm actuatedzby an electriclamotorof the magnetic having apair of Icoacting contact arms supportedthereby ininsulated spaced relation to .each other, m fllnsconnecting the contact arms in series in the electric motor circuit including a contact platemounted in said contact stack in insulated spaced relation to said contact arms, said contact, platebeing extended to form a shelf atone side of the ,contact arms, a relay switch for closinga circuit through said contact arms having the core thereof secured to said contact plate shelf and electrically connected therewitha coil on saidcore having one side electrically connected with the shelf and the other .side electrically connected to said terminal, meansresiliently and electrically connecting the relay armature with one of the contact arms, and a pair of coactingcontacts connected respectively with said relay core and armature moved intofland out of engagement with each -.type.and a lcu-rrentsupply circuitfor said motor includinga source of potential; and a terminal mountedjin-theihorn structure, a contact stack in electrical contact therewith adapted to be other during the o eration of the relay armature for closing the motor circuit.

6. In a warning signal provided-with a vibratorydiaphragm and an, electric motor of the magnetic type having the armature thereof connected to the diaphragm for operating the same,

in combination, a contact stack including a frame member, a' pair of contact armsmounted on said franne in insulated spaced relation thereto and to each other, a contact" plate mounted on said frame in insulated spaced relation thereto and to said contact arms, means" for electrically connecting one of the contact arms with the electric motontmeansprovidingacircuit from the contact plate to 'the second con-tact arm including a relay having the "core thereof supportably secured to the contact plate in electrical contact therewith and the armature thereof resiliently supported by and electrically connected with saidsecond contact arm, a pair of coasting contact'e'leinents connected respectively'with said relay core andfarmature in "electrical contact therewithahd' engageable with each otherwhen the armature is actuated upon said core being magnetized, and means for magnetizing said core.

7. In a contact stack for an electric motor of the magnetic type,a supporting frame, an electric circuit for said motor including a source of potential, a contact plate adapted to be connectedwith onc'side of said source of potential and mounted on said frame in insulated spaced relation thereto, a pair of contact arms mounted on the frame in lnsulated'spaced relation thereto and to said contact plate, means electrically connecting the relay'core with said contact arms.

THEODORE J SCOFIELD. 

